#115 Why is Spirytus not 100 proof? The unbreakable wall of 96 degrees

Brewing alone has a limit on alcohol content.

Brewed liquors like wine and sake rely on yeast consuming sugar to produce alcohol. However, because the yeast itself is overwhelmed by the alcohol, the limit is around 15% to 20% at most. To achieve higher percentages, a process called distillation, which utilizes differences in boiling points, is indispensable.

Repeating distillation over and over increases the concentration.

The boiling point of ethanol is 78.4°C and water is 100°C. While ethanol is driven off using this difference in boiling points, water inevitably evaporates alongside it. In plants, distillation towers are used to repeatedly distill the liquid, increasing the concentration step by step to 50%, 60%, and 70%.

Finally, we hit the insurmountable wall of 96 degrees.

However, once the alcohol content exceeds 96 degrees, a phenomenon called azeotropy occurs where the concentrations of the vapor and liquid become identical, meaning no matter how many times you distill it, the concentration won't get any higher. This is the reason why Spirytus is 96 degrees, but there is a certain development waiting for you beyond this point. Please listen to the main episode to find out more.